“…At last, high‐purity argon was introduced into the furnace chamber through the deoxygenation tube (JSH‐1), and the flow rate was adjusted to 200 mL min −1 . According to the data from the manufacturer of the deoxygenation tube, the oxygen partial pressure () in the furnace chamber was about 1.87 × 10 −3 Pa. [ 25 ] The furnace was heated up (5 K min −1 ) after the cooling water was turned on. When the steel sample was about to melt, the camera was turned on to capture the image at a frequency of 1 fps.…”